Testing wells



Oct. 22, 1963 D. H. FLICKINGER 3,107,725

TESTING WELLS Filed Dec. 5, 1960 4 sheets-sneak 1 52 l 8U k H 30 r 1H m2| y I DON H. FLICKINGER IN VEN TOR.

BY FIG. 1A

ATTORNEY.

Oct. 22, 6 D. H. FLICKINGER TESTING WELLS 4 Sheets-Sheet 2 Filed Dec. 5,1960 FIG. 2B

DON H. FLICKINGER INVENTOR.

By M

FIG. 2A

AT TORNE Y.-.

Oct. 22, 1963 H. FLICKINGER TESTING WELLS 4 Sheets-Sheet 3 DON H.FLICKINGER INVENTOR.

' ATTORNEY Filed Dec. 5, 1960 Oct. 22, 1963 D. H. FLlCK lNGER TESTINGwELLs 4 Sheets-Sheet 4 Filed Dec. 5, 1960 DON H. FLICKINGER IN VEN TOR.

Kw/W

ATTORNE Y.

United States Patent can Petroleum Corporation, Tulsa, Okla, acorporation of Delaware Filed Dec. 5, 1960, Ser. No. 73,909 Claims. (Cl.166-3) This invention relates to testing wells. More specifically, itrelates to the well testing method and apparatus in which a conduit islowered into a well, a'packer is set between the conduit and the wellwall to isolate a zone of the well below the packer and fluids from theisolated zone are allowed to flow up inside the conduit.

A convenient form of well testing equipment uses a packer which can beset by hydraulic pressure. An example of such equipment is described indetail in US. Patent 2,611,437 Lynes. In the equipment described in theLynes patent, pressure is applied through the conduit to inflate apacker or packers after which the conduit is manipulated by turning,raising or lowering, or a combina tion of motions to close the packerinflating ports and open one or more ports which connect the conduit andthe zone to be tested.

The use of inflatable packers as just described offers a veryadvantageous system except for the necessity of removing the liquidnormally used in the conduit to exert the pressure necessary to set thepackers. This liquid must be removed to decrease the pressure on thezone to be tested so fluids can enter the conduit from this zone.Recently this difficulty has been partly solved by using a gas toactuate the packers. That is, the conduit and well testing equipment,including the packers, are run into the well empty. The gas underpressure is introduced into the top of the conduit from containers ofcompressed gas, by means of compressors or by use of liquefied gas. Thegas pressure in the conduit is increased to a value suflicient to setthe packers. After the packer inflation ports are closed, the pressurein the conduit is released by opening a valve at the surface to permitescape of the gas. Increasing the gas pressure in the conduit to thedesired level has proved to be a time-consuming operation. In addition,the expense and inconvenience of transporting either large containers ofcompressed gas or a gas compressor to the well is an objectionablefeature.

An object of this invention is to provide a method and apparatus forwell testing in which the conduit and well testing equipment can be runempty and the hydraulically settable packer or packers can be actuatedwithout the use of compressors, containers of compressed gas, or thelike at the surface of the earth. Other objects will be apparent fromthe following description and claims.

In general, I accomplish the objects of my invention by the use of agas-generating charge lowered into the well on a wire line or electriccable. The container of the charge is a pressure vessel which is lockedin sealed engagement with the well testing equipment after the containerreaches the desired location near the bottom of the conduit so that thegas which is generated exerts pressure only on the well testingequipment and a small volume of the conduit near the well testingequipment. After the high-pressure gas has expanded the packers, eachpacker is locked in expanded position. The gas-generating chargecontainer can then be released and withdrawn after which the welltesting procedure can be carried out as usual.

My apparatus and method will be better understood from a considerationof the drawing in which:

FIGURES 1A and 1B present a vertical view in crosssection of oneembodiment of well testing equipment suitable for my purposes;

FIGURES 2A and 2B present a cross-sectional view of one form of agas-generating equipment suitable for my 3,107,725 Patented Oct. 22.,1963 purposes together with associated means for locking the equipmentin sealed engagement with the well testing equipment shown in FIGURES 1Aand 18;

FIGURE 3 is a view in vertical cross-section of another form ofgas-generating equipment;

FIGURE 4 is a view in vertical cross-section of a mechanism for lockingthe equipment of FIGURE 3 in sealed engagement with the equipment shownin FIGURE 1.

Considering the figures in more detail, in FIGURES 1A and 1B, an outersleeve or mandrel 10 carries packers 11. The ends of the packers aresecured to sleeve 10 by clamps 1-2. An inner sleeve 13 is slidablymounted within outer sleeve 10. Sleeve 13 slides within sleeve 10 withinlimits imposed by flange -14 operating in chamber 15 which is anenlarged portion of outer sleeve 10. Upward motion of sleeve 13 islimited by flange 1 4 striking a retainer ring 16 and lower motion islimited by the bottom surface 17 of chamber 15. Flange 14 is preventedfrom turning incharnber 15 by extensions 18 sliding in grooves 19 in thewall of chamber 15. Inner sleeve 13 is supported by conduit 20 throughconnector 21. Conduit 20 is preferably drill pipe but may be tubing ofsteel or the like which is sufiiciently thick walled to withstand thepressure di ferentials involved. At the bottom of inner sleeve 13, ports22 may be sealed by plug or go-devil 2 3 including retrieving head 24.Near the top of sleeve 13 is a relief valve 25 which prevents developingsuflicient pressure in sleeve 13 to damage packers 11. Outer sleeve 10includes ports or passages 30, communicating with the interior ofpackers 1'1 and ports or passages 31, communicating with any well zoneisolated by the packers 11. Ports 32 in inner sleeve 13 are aligned withports 30 in outer sleeve '10 when inner sleeve 13 is in its upperposition with respect to sleeve 10. Ports 3 3 in inner sleeve 13' arealigned with ports 31 in outer sleeve 10 when inner sleeve 13 is at ornear its lower position with respect to outer sleeve 10.

The equipment in FIGURES 1A and 1B is shown in a somewhat diagrammaticform. More detailed drawings of this type of equipment may be found inUS. Patent 2,611,437 which was previously mentioned. Inflatable packersof still other designs can, of course, also be used. In addition, it ispossible to use packers in which a sleeve of resilient packing materialis squeezed between two rings, the compressive force being provided byhydraulic pressure acting on a piston connected to one ring and acylinder connected to the other. A packer of this sort is shown in moredetail in US. Patent 2,760,583, for example. Still other packers whichcan be set by the action of hydraulic pressure will occur to thoseskilled in the art. The infiatable packers are preferred, howevenbecause out their simplicity.

The apparatus of FIGURES 2A :and 2B is shown on a considerably largerscale, than that of FIGURES 1A and IE to permit a better showing ofdetails. The entire apparatus of FIGURES 2A and'ZB is designed to belowered through the conduit 20 of FIGURE 1A. Gas-generating charge 40,preferably a slow-burning propellant, is enclosed in pressure chamber orcontainer 41 which is lowered into the well or reinforced electric cable42. An electric lead 43 in the cable passes through an insulated seal(not shown) and is attached to a blasting cap 44 in the end of explosivecharge 40. The other lead 45 to the blasting cap can be grounded or canbe connected to another lead in cable 42. A small orifice 39 is providedin the wall of container 41.

A mandrel 46 is attached to the bottom of container 41. A passage 47 isprovided through the center of mandrel 46. Slips 5 1 are mounted onpistons 52 in the wall of mandrel 46. Fluid pressure inside passages 47acts through ports 53 against pistons 52 to compress springs 54 againstretainer rings 55 to cause outward motion of slips 51 from the center ofmandrel 46. These slips are enemas designed to lock the gas-generatingcharge and associated equipment in conduit 2%.

Attached to the bottom of slip mandrel 46 is packer mandrel 56. Packer57 is mounted on mandrel '56. This packer is preferably of thedownwardly-facing cup type. Below packer 57 expanding cone 53 isslidably mounted on mandrel 56. Sliding motion of cone 58 is limited byflange 59 onmandrel 56. The cone is normally held in retracted position,as shown in FIGURE 2B, by springs 6%1 acting against flange 59 andretainer ring 61. Ports 62 are provided through the Wall of packermandrel 56 below the base of cone 58. Passage 63 is provided through thecenter of mandrel 56- and is aligned with passage 47 through slipsmandrel 46. Ports 62 thus expose the bottom of cone 58 to any pressurewithin passage 63. The base of cone 58 is surrounded by sleeve 64 whichacts as a cylinder in which cone 58 can act as a piston when exposed topressure in passage 63 acting through ports 62. The bottom of theannular space between mandrel 56 and sleeve 64 is sealed by a baseelement 65. This base '66 includes a passage 67 aligned with passage 63in mandrel 56. The bottom of passage 67 is closed by a shear disc 68which is held in place by cap 69.

In operation, the apparatus of FIGURES 2A and 2B, which may be termedthe gas-generating equipment, is lowered through conduit 20 after thewell testing equipment of FIGURES 1A and 1B has been run on conduit 26to the desired level in the well. The gas-generating equipment ispreferably run to a point as close as possible above the well testingequipment to avoid the need for filling a large volume of conduit 20with compressed gas. When the gas-generating equipment reaches thedesired level, an electric current is sent down conductor 43 to detonateblasting cap 44 and actuate gas-generating change 46. The gases enterpassages 47 and 63 in mandrels 46 and 56, respectively, locking thegas-generating equipment in sealed engagement with conduit 20 and,therefore, with the well testing equipment. Shear disc -68 holds thegases within the gas-generating equipment until the slips and packer aresolidly set. When the pressure reaches some predetermined value, such as1,000 pounds per square inch, disc 68 ruptures, allowing the gas to passinto conduit 20' and through ports 30' and 32 of the packers 11 whichare expanded to isolate a desired zone of the well to be tested. If anexcessive pressure develops, this is relieved through safety valve 25.

Packers 11 are sealed in expanded condition by lowering conduit Ztl.Contact of expanded packers 11 with the wall of the well presentsdownward motion of sleeve It), so sleeve 13 moves downwardly withrespect to sleeve 10. The gases within the gas-generating equipment andwell testing equipment slowly leak out through orifice 39 to equalizepressures inside and outside of mandrels 4-6 (and 56. When pressuresapproach being equalized across these mandrels, springs 54 withdrawslips 51 and spring 60 withdraws cone 58 permitting packer 57 tocollapse. This allows withdrawing the generating equipment from thewell. Testing of the Well can then proceed by further lowering ofconduit 20* to align ports 31 and 33. This permits fluids from theisolated zone of the well to flow into conduit 20 through which they canflow to the surface. If the zone has insufiicient pressure to causefluids to allow to the surface, a sample can be obtained by use ofsuitable apparatus such as a wire line bailer, for example After thewell test, conduit 20 can be raised to realign ports 30 and 32 andpermit packers 11 to collapse. The conduit and equipment can then bewithdrawn from the well. If the conduit contains considerable liquid, itmay be desirable to run a wire line fishing tool to engage fishing head24 on go-devil 23 and remove it from the well. This opens ports 2210permit pulling a dry string.

In most wells the gas-generating equipment shown in FIGURES 2A and 2Bwill be found to be completelysatisfactory. It is to be noted, however,that in my method the well testing equipment and conduit are run insubstantially empty condition. Therefore, when the gas-generating chargeis fired, the entire pressure required to expand the packers against thepressure of the well will be imposed upwardly against the packers andslips of the gas-generating equipment. In a deep well, this pressure mayreach a value of 10,000 pounds per square inch or even more. The totalforce tending to blow the gas-generating equipment up the hole is theproduct of this pressure and the internal cross-sectional area ofconduit 20, which may be considerable. In such extreme cases, it may bepreferred to use a somewhat more positive means for locking thegas-generating equipment in sealed engagement with the well testingequipment. This is a critical requirement in my process. Such apparatusis shown in FIGURES 3 and 4.

In these figures, the apparatus of FIGURE 4 is a lower extension of theapparatus shown in FIGURE 3. As in FIGURES 2A and 2B, the gas-generatingand the locking and sealing equipment are designed to be lowered throughconduit 26 which is shown in FIGURE 4.

In this case, however, conduit 21] includes, just above the well testingequipment, a seating nipple 70.

The apparatus of FIGURE 4 is simply an Otis removable mandrel assembly.In this apparatus dog-carrier 71 supports dogs 72 which latch in seatingnipple 70. Extending through dog-carrier 71 is carrying mandrel 73 whichsupports locking mandrel 74 below the dogs. Below locking mandrel 74 ispacking mandrel 75 with packing 76. The top pontion of carrier. mandrel73 and dogcarrier 71 are modified :as shown in FIGURE 3.

On the top of mandrel 73 is mounted a container 81 for a gas-generatingchange. 82. The top of container 81 is closed by cap 83 which includes aneck 84 and a flange .85 on the top of neck 84. Flange 35 is enclosedby, and slides in, a chamber 86 with a retainer ring 87. A flangeextension 88 moves in groove 89 in the wall of chamber 86 to maintainpin 90 in alignment with port 91 in the top of check valve assembly 92.

The entire gas-generating assembly is supported by an electric cable 93attached to ring 9 4 on chamber 86. Electric lead 95 passes through seal96 in cap 83 to blasting cap 97 in gas-generating charge 2. The otherelectric lead to the blasting cap is grounded at 98 as shown, or maypass through a seal in cap 83 and be connected to another lead in cable93. A shear disc 99 may be provided to seal the bottom port in chamber81 and the passage in mandrel 73.

Spring arms 101 attached to the bottom of container 81 have end portions102 bent to engage head 103 on dog-carrier 7-1. In one position of cams104, ends 102 on arms 101 are held out so that they do not engage head19 3. In the other position of cams 1G4, arms 101 are allowed to springinwardly to a position where they do engage head 103. The position ofcams 104 is controlled by gears 105 which are actuated by spring arms106 attached to head 103. Spring arms 106 and gears 105 act as a ratchetmechanism so that on alternate strokes of mandrel 73 sliding up and downthrough dog-carrier 71 anms 101 are held away from head 103 or areallowed to spring in and engage head 163. Other ratchet;

and cam designs will occur to those skilled in the art.

In operation the gas-generating equipment of FIG- URES 3 and 4 islowered through conduit 20 with cams 104 in the positions shown inFIGURE 3 until packing the well testing equipment. Gas-generating charge82 can then be actuated to set packers 11 of the well testing equipmentas described previously in connection with the apparatus of FIGURE 2.

As soon as the packers of the well testing equipment are set, cable 93can be slacked oil to allow pin 90 to open check valve 92 and equalizethe pressures above and below the gas-generating equipment. When thesepressures are equalized, further reciprocating of chamber 86 on flange-85 drives locking mandrel 74 downwardly and releases dogs 72 so thegas-generating equipment can be withdrawn from the well.

When the packers were first driven down into seating nipple 70, carryingmandrel 73- rnoved downwardly with respect to dog-carrier 71, permittingspring arms 106 to pass up past gears .105. When an'upward strain wasimposed on cable 93 to bring locking mandrel 74 into engagement withdogs 72, cams 104 moved up with respect to spring arms 1%, causing theends of these arms to turn gears -5 and cams 1%4 one quarter of a turn.This allowed spring arms 161 to spring inwardly to a position where theywould engage head 103- when lowered again. Thus, when carrier mandrel 73was again driven down to release the dogs, bent ends 102 of arms 101engaged head .103 permitting lifting the gas-generating assembly out ofthe well.

After the gas-generating equipment is removed, conduit 29 can bemanipulated to align ports 31 and 33 to make the well test, aspreviously described. It will be apparent that still other designs ofgas-generating equipment assemblies can be used if they are subject tobeing locked in sealed engagement with the well testing equipment asrequired in my method and then being released. A considerable variationis permissible in still other aspects of the apparatus and method.

For example, the preferred form of gas-generating charge is a stickmolded of a solid rocket propellant such as ammonium nitrate in a matrixof rubber, cellulose acetate, or the like. Many such solid rocketpropellants are now available having various burning rates. Still otherexplosives of widely different burning rates are described, for example,in US. Patent 2,740,478 Greene. The class may be conveniently defined asexplosive propellants. Still other forms of gas-generating charges maybe used. These may, for example, take the form of cylinders of highlycompressed gases such as nitrogen. The compressed gases are particularlyuseful at shallow well depths where only moderate pressures arerequired. Still other gas-generating charges will occur to those skilledin the art.

Another permissible variation is to run the gas-generating assembly onan uninsulated wire line and drop a godevil down the wire line toactuate the gas-generating charge. While a two-packer system has beenshown and described, it will be apparent that the lower packer can beomitted if it is desired to test the entire portion of the well belowthe top packer.

My method has been described to this point as a way of testing a singleZone in a well. Sometimes it is found that when ports 31 and -33 betweenthe packers are aligned, little, if any, liquids enter the conduit fromthe zone isolated between the packers. In this case, it is frequentlydesirable to move the well testing equipment to a new level in the welland run another test. My apparatus and method are well adapted to suchoperations. It is only necessary to raise conduit to close ports 31 andrealign ports 3% and 32. This collapses the packers. The well testingequipment can then be moved to another level in the well where thepackers are reset and a new well test is run in the same manner as thefirst test.

Sometimes a moderate amount of liquids may enter the conduit during thefirst test. Such liquids may be removed by use of a wire line bailer,for example, if desired. The second test can then be run as describedabove. It should be noted, however, that it is not necessary to removeall the liquids from the bottom of the well testing equipment. In fact,I prefer to have sufficient liquid present in the equipment and conduit20 to fill the packers plus enough to fill sleeve 13 at least to thelevel of ports 32. The reason is that liquids are relativelyincompressible compared to gases. The gases from an explosive charge arehot. If the packer is inflated with the hot gases and the packerinflation ports are closed, the pressure inside the packers falls as thegases cool. If the hot gases are used to force a liquid into thepackers, however, the pressure inside the packers does not drop afterthe inflation ports are sealed. In addition, a gas-inflated packer issomewhat more easily deformed than a liquid-filled packer due to thecompressible nature of the gas. Therefore, even when a cylinder ofcompressed gas is used as the gas-generating charge and the gas is nothot, it is preferable to arrange for the packers to be actuated by aliquid driven by the gas, rather than actuating the packers by the gasitself.

It will be understood, in view of the desirability to have a limitedamount of liquid in the equipment, that when reference is made to theconduit and equipment being substantially empty, it is contemplated thatsufilcient liquid may be present to fill the packers and sleeves to apoint above the packer-inflating ports, or even to a point slightlyabove the entire well testing equipment. Likewise, when reference ismade to removing excess liquid from the conduit after a first test andbefore a second test, it is also contemplated that sufiicient liquid maybe left to fill the equipment as first described.

It will be apparent from the above that I have provided a method andapparatus which accomplish the objects of my invention. By using agas-generating charge which can be run on a cable, locked in sealedengagement with well testing equipment, and later can be released andwithdrawn, it is possible to obtain all the benefits of running the welltesting equipment substantially empty, without the necessity of largenumbers of compressed gas cylinders or of gas compressing equipment atthe surface to increase the pressure within the entire conduit leadingto the well testing equipment.

I claim:

1. A method for testing a well comprising running into the well, on aconduit, testing equipment including at least one packer for isolatingthe zone in the well to be tested, said packer being of the type whichis set by pressure in said conduit, said conduit and testing equipmentbeing run substantially empty of liquids, lowering into said wellthrough said conduit gas-generating apparatus including a gas-generatingcharge, locking said gas-generating apparatus in sealed engagement withsaid testing equipment, actuating said gas generating charge whereby gaspressure is developed which sets said packer, locking said packer in setcondition, disengaging said gasgenerating apparatus from said testingequipment, and opening a port in said equipment, said port connectingsaid conduit to the isolated zone of the well, and determining theamount and nature of fluids entering said conduit.

2. The method of claim 1 in which after said test has been made, saidport is closed, the pressure is released to unseat said packer, liquidin the conduit from the first test is removed until the conduit is againsubstantially empty, said equipment is moved to a new location in saidwell, gas-generating apparatus including a new gasgenerating charge isrun, locked into sealed engagement with said well testing equipment, andsaid new gas-gem erating charge is actuated to generate gas pressurewhich sets said at least one packer, and said port is reopened to obtaina second test in said well without removing said equipment from saidwell.

3. The method of claim 1 in which said packer is of the hydraulicallyinflatable type and, before setting said packer, suflicient liquid isintroduced into said well testing equipment to insure that said at leastone packer is filled with said liquid rather than with gas from saidgasgenerating charge.

4. Well testing apparatus comprising a fluid conduit, a tubular mandrelmounted on said conduit in alignment with said conduit, at least onefluid pressure expansible packer surrounding said mandrel, means forlocking said packer in set condition, a gas-generating charge, acontainer for said charge, means for locking said container in sealedengagement with said conduit above said packer, means for actuating saidcharge, to discharge gas to expand said packer, means for releasing saidmeans for locking said container in sealed engagement with said packer,a port in said mandrel below said packer, said port connecting theinside of said conduit to the isolated zone of the well below saidpacker, and means for opening and closing said port.

5. Well testing apparatus comprising an outer sleeve, inflatable packerssurrounding said outer sleeve, said sleeve including a port opposite theinterior of each of said packers and a port between said packers, aninner sleeve disposed within said outer sleeve, said inner sleeve beingslidable within limits Within said outer sleeve, said inner sleeveincluding ports capable of being aligned with said ports in said outersleeve, opposite the interiors of said packers, and a port capable ofbeing aligned with .said port, in said outer sleeve, between saidpackers, said 8 ports in said inner sleeve being so arranged that theports in the inner and outer sleeves between the packers are not inalignment when the ports in the inner and outer sleeves opposite theinteriors of said packers are in alignment and vice versa, a conduitattached to said inner sleeve for lowering said sleeves and packers intosaid Well, a gas-generating charge, a container for said charge,

said container being capable of being lowered through said conduit,means for actuating said charge, means for locking said container insealed engagement with said conduit above said sleeves, means forreleasing said container, and means for loweringsaid charge andcontainer through said conduit and removing said container from saidconduit.

References Cited in the file of this patent UNITED STATES PATENTS Clarket al. May 29, 1962

1. A METHOD FOR TESTING A WELL COMPRISING RUNNING INTO THE WELL, ON ACONDUIT, TESTING EQUIPMENT INCLUDING AT LEAST ONE PACKER FOR ISOLATINGTHE ZONE IN THE WELL TO BE TESTED, SAID PACKER BEING OF THE TYPE WHICHIS SET BY PRESSURE IN SAID CONDUIT, SAID CONDUIT AND TESTING EQUIPMENTBEING RUN SUBSTANTIALLY EMPTY OF LIQUIDS, LOWERING INTO SAID WELLTHROUGH SAID CONDUIT GAS-GENERATING APPARATUS INCLUDING A GAS-GENERATINGCHARGE, LOCKING SAID GAS-GENERATING APPARATUS IN SEALED ENGAGEMENT WITHSAID TESTING EQUIPMENT, ACTUATING SAID GAS GENERATING CHARGE WHEREBY GASPRESSURE IS DEVELOPED WHICH SETS SAID PACKER, LOCKING SAID PACKER IN SETCONDITION, DISENGAGING SAID GASGENERATING APPARATUS FROM SAID TESTINGEQUIPMENT, AND OPENING A PORT IN SAID EQUIPMENT, SAID PORT CONNECTINGSAID CONDUIT TO THE ISOLATED ZONE OF THE WELL, AND DETERMINING THEAMOUNT AND NATURE OF FLUIDS ENTERING SAID CONDUIT.